Introduction: REV7 functions in various biological processes, including the DNA damage response. REV7 expression has been linked to the prognosis and chemoresistance in several human cancers. This study investigated the significance of REV7 in gallbladder adenocarcinoma (GBAC). Methods: REV7 expression was examined immunohistochemically in 77 resected GBAC specimens, and its association with clinicopathological features was analyzed. REV7-depleted GBAC cell lines were established, and the biological effects of REV7 depletion were evaluated. Results: High REV7 expression in GBAC tissues correlated with increased cell proliferation, as assessed by Ki-67 labeling indices (p < 0.001), and was associated with a trend toward shorter overall survival (p = 0.070) and significantly shorter post-progression survival (p = 0.035). REV7-knockout and REV7-knockdown cell lines derived from NOZ and G415 GBAC cells (NOZ-KO and G415-KD, respectively) showed reduced proliferation and increased sensitivity to cisplatin; however, REV7 depletion did not affect cell migration and invasion. Reintroduction of REV7 into NOZ-KO cells restores chemoresistance. Furthermore, RNA sequencing analysis comparing wild-type NOZ and NOZ-KOs revealed that REV7 inactivation downregulates genes involved in the DNA damage response. Conclusion: REV7 may contribute to tumor progression and chemoresistance in GBAC and may serve as a prognostic biomarker and molecular target for GBAC management.

Introduction: Testicular germ cell tumors (TGCTs) are the most common solid malignancies among young men. Despite good response to cisplatin-based chemotherapy, side effects negatively affect quality of life. Recent development of ecto-nucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) inhibitors opens opportunity for targeted therapy, but ENPP1 expression in TGCTs has not been characterized. We aimed to assess ENPP1 immunoexpression in a cohort of primary and metastatic TGCTs, and in normal testicular parenchyma, looking into differential immunoexpression patterns among subtypes and clinicopathological correlations. Methods: Overall, 90 TGCT individual tumor components from 63 patients diagnosed and treated at a comprehensive cancer center were assessed, using immunohistochemistry to ascertain biomarker expression (combined score of stained tumor cells percentage and intensity). In silico analysis of The Cancer Genome Atlas (TCGA) and Human Protein Atlas (HPA) datasets was performed for additional validation. Results: Significant differences in ENPP1 expression across TGCT subtypes were disclosed. Seminomas and embryonal carcinomas (ECs) showed significantly higher ENPP1 expression compared to other subtypes, the highest levels being found in EC, which was confirmed with in silico analysis of TCGA and HPA. Expression in metastatic samples was overall lower compared to primary TGCTs. ENPP1 was not expressed in germ cells of healthy testicular parenchyma. Conclusion: We demonstrate that ENPP1 is expressed in TGCTs, mostly EC (a frequently aggressive tumor subtype), followed by seminoma (the most common TGCT subtype), suggesting potential responsiveness to novel ENPP1 inhibitors. Absent expression in germ cells of healthy testicular parenchyma suggest cancer cells specificity and low probability of fertility-related toxicity.

Introduction: Keratin (KRT) 24 is a cytoskeletal protein that plays a major role in the formation of intermediate filaments to provide mechanical stability. KRT24 overexpression facilitates tumour cell migration, invasion, and metastasis in several types of cancers. This study evaluates the clinicopathological significance of KRT24 expression in large breast cancer (BC) cohorts with long-term follow-up. Methods: KRT24 mRNA expression was assessed in publicly available BC datasets (n = 13,025). KRT24 protein expression was evaluated immunohistochemically using well-characterised operable BC cohort (n = 832), and associations with clinicopathological features and patients’ outcomes were evaluated. Results: The KRT24 expression, at both transcriptomic and protein levels, was associated with features indicative of poor prognosis, including high histological grade, ER negativity, and HER2 positivity, and with poor patient outcomes. High KRT24 protein expression in chemotherapy-treated patients was significantly correlated with a shorter survival, a higher risk of distant metastases, and BC-related deaths. Additionally, patients with high KRT24 mRNA expression exhibited dysregulation of several differentially expressed genes and enriched pathways, including the cytokine-cytokine receptor interaction pathway, IL-17 signalling pathway, and oestrogen signalling pathway. Conclusion: KRT24 expression is associated with poor prognosis in BC. It also plays a predictive role in advanced BC and may represent a potential therapeutic target for patients with this aggressive disease.

Introduction: Papillary renal neoplasm with reverse polarity (PRNRP) is an emerging entity characterized by distinctive histomorphological and molecular features. Often identified incidentally in imaging studies, its accurate diagnosis is essential considering its favorable prognosis. However, its cytological features need further characterization, since only one single publication with 2 cases diagnosed in fine-needle aspiration biopsies have been reported to date. Case Presentation: We report the case of a 70-year-old man recently diagnosed with primary lung adenocarcinoma. Fine-needle aspiration biopsy of a 15-mm nodule in the left kidney revealed cytological features consistent with a papillary neoplasm with eosinophilic features. Immunocytochemistry showed positivity for PAX-8, CK7, and GATA3 and negativity for TTF-1. Next-generation sequencing (NGS) identified a KRAS G12V mutation. Altogether, these findings enabled the diagnosis of PRNRP. The patient underwent conservative management of the renal tumor, which did not recur at 8 months since diagnosis. Conclusion: PRNRP is a recently described tumor which can be managed conservatively. We describe the third case of PRNRP diagnosed on fine-needle aspiration biopsy, which enabled several diagnostic studies, including immunocytochemistry and NGS confirmation. With this case, we highlight the increasing role of fine-needle aspiration biopsy in the clinical management of a subset of patients with small renal masses.

Introduction: Prostate cancer (PCa) is the most frequently diagnosed cancer among men. A major clinical need is to accurately predict clinically significant PCa (csPCa). A proteomics-based 19-biomarker model (19-BM) was previously developed using capillary electrophoresis-mass spectrometry (CE-MS) and validated in close to 1,000 patients at risk for PCa. This study aimed to validate 19-BM in a multicenter prospective cohort of 101 biopsy-naive patients using current diagnostic pathways. Methods: Urine samples from 101 patients with suspicious of PCa were analyzed using CE-MS. All patients underwent multiparametric or magnetic resonance imaging (mpMRI) using a 3-T system. The 19-BM score was estimated using support vector machine-based software (MosaCluster v1.7.0), employing the previously published cut-off criterion of −0.07. Diagnostic nomograms were investigated along with mpMRI. Results: Independent validation of 19-BM yielded a sensitivity of 77% and a specificity of 85% (AUC:0.81). This performance surpassed those of prostate-specific antigen (PSA; AUC:0.56) and PSA density (AUC:0.69). For PI-RADS≤ 3 patients, 19-BM showed a sensitivity of 86% and a specificity of 88%. Integrating 19-BM with mpMRI resulted in significantly better accuracy (AUC:0.90) compared to individual investigations alone (AUC19BM = 0.81; p = 0.004 and AUCmpMRI: 0.79; p = 0.001). Examining the decision curve analysis, 19-BM with mpMRI surpassed other approaches for the prevailing risk interval from a 30% cut-off. Conclusions: 19-BM exhibited favorable reproducibility for the prediction of csPCa. In patients with PI-RADS ≤3, 19-BM correctly classified 88% of the patients with insignificant PCa at the cost of 1 missed csPCa patient. Utilizing the 19-BM test could prove valuable in complementing mpMRI and reducing the need for unnecessary biopsies.

Introduction: Chronic lymphocytic leukemia (CLL) is the most common type of leukemia in the Western countries and is very rare in Asia. Methods: Peripheral blood or bone marrow mononuclear cells obtained at initial diagnosis from 215 patients with CLL were analyzed by using next-generation sequencing to investigate the ethnic differences in genetic abnormalities. Results: Whole-genome sequencing and whole-exome sequencing analyses on 30 cases showed that 9 genes, including IGLL5, MYD88, TCHH, DSCAM, AXDND1, BICRA, KMT2D, MYT1L, and RBM43, were more frequently mutated in our Taiwanese cohort compared with those of the Western cohorts. IGLL5, MYD88, and KMT2D genes were further analyzed by targeted sequencing in another 185 CLL patients, unraveling frequencies of 29.3%, 20.9%, and 15.0%, respectively. The most frequent positional mutation of MYD88 was V217F (26/45, 57.8%), followed by L265P (9/45, 20.0%). MYD88 mutations were significantly associated with IGLL5 mutations (p = 0.0004), mutated IGHV (p < 0.0001) and 13q deletion (p = 0.0164). CLL patients with co-occurrence of MYD88 mutations with KMT2D or/and IGLL5 mutations were associated with a significantly inferior survival compared to those with MYD88 mutation alone (not reached vs. 131.8 months, p = 0.007). In multivariate analysis, MYD88 mutation without KMT2D or IGLL5 mutations was an independently favorable predictor. Conclusions: IGLL5, MYD88, and KMT2D mutations were enriched in Taiwanese CLL, and co-occurrence of MYD88 mutations with KMT2D or/and IGLL5 mutations was associated with a poorer prognosis. Introduction: Chronic lymphocytic leukemia (CLL) is the most common type of leukemia in the Western countries and is very rare in Asia. Methods: Peripheral blood or bone marrow mononuclear cells obtained at initial diagnosis from 215 patients with CLL were analyzed by using next-generation sequencing to investigate the ethnic differences in genetic abnormalities. Results: Whole-genome sequencing and whole-exome sequencing analyses on 30 cases showed that 9 genes, including IGLL5, MYD88, TCHH, DSCAM, AXDND1, BICRA, KMT2D, MYT1L, and RBM43, were more frequently mutated in our Taiwanese cohort compared with those of the Western cohorts. IGLL5, MYD88, and KMT2D genes were further analyzed by targeted sequencing in another 185 CLL patients, unraveling frequencies of 29.3%, 20.9%, and 15.0%, respectively. The most frequent positional mutation of MYD88 was V217F (26/45, 57.8%), followed by L265P (9/45, 20.0%). MYD88 mutations were significantly associated with IGLL5 mutations (p = 0.0004), mutated IGHV (p < 0.0001) and 13q deletion (p = 0.0164). CLL patients with co-occurrence of MYD88 mutations with KMT2D or/and IGLL5 mutations were associated with a significantly inferior survival compared to those with MYD88 mutation alone (not reached vs. 131.8 months, p = 0.007). In multivariate analysis, MYD88 mutation without KMT2D or IGLL5 mutations was an independently favorable predictor. Conclusions: IGLL5, MYD88, and KMT2D mutations were enriched in Taiwanese CLL, and co-occurrence of MYD88 mutations with KMT2D or/and IGLL5 mutations was associated with a poorer prognosis.

Introduction: Defining the origin of metastatic cancer is crucial for establishing an optimal treatment strategy, especially when obtaining sufficient tissue from secondary malignancies is limited. While cytological examination is often used in this diagnostic setting, morphologic analysis alone often fails to differentiate metastases derived from the breast from other primaries. The hormone receptor, human epidermal growth factor receptor-2, gross cystic disease fluid protein 15, and mammaglobin immunohistochemistry are often used to diagnose metastatic breast cancer. However, their effectiveness decreases in estrogen receptor (ER)-negative breast cancers, including the triple-negative breast cancer (TNBC) subtype. Methods: We conducted a comprehensive evaluation of GATA-binding protein 3 (GATA-3), trichorhinophalangeal syndrome type 1 (TRPS-1), and Matrix Gla Protein (MGP) immunochemistry across 140 effusion cytology specimens with metastatic adenocarcinoma derived from various primaries, including the breast, colon, pancreaticobiliary, lung, tubo-ovarian, and stomach. Results: The expression rates of these immunomarkers were significantly higher in metastatic cancers originating from the breast than other primaries. In TNBC, TRPS-1 (80.00%) and MGP (65.00%) exhibited higher positivity rates compared to GATA-3 (40.00%). Additionally, our data suggest that an immunohistochemical panel comprising MGP, GATA-3, and TRPS-1 significantly enhances the detection of metastatic breast cancer in effusion cytology specimens, including TNBC in particular. When considering dual-marker positivity, the diagnostic accuracy was found to be 89.29% across all breast cancer subtypes and 92.93% for TNBC. Conclusions: MGP appears to be a robust marker for identifying metastatic breast cancer in malignant effusions, especially TNBC. MGP notably enhances diagnostic accuracy when incorporated together with GATA-3 and TRPS-1 in an immunohistochemical panel.

Introduction: The tumor microenvironment of sarcomas has not been studied in detail; in particular, little is known about cancer-associated fibroblasts (CAFs). Sarcoma cells are difficult to distinguish from CAFs, either histomorphologically or immunohistochemically. Methods: We scored the expression of individual CAF markers (fibroblast-activating protein [FAP], CD10, and podoplanin) in the intratumoral and marginal areas of 133 sarcomas. We also examined the association between these markers, as well as the number of CD163-positive macrophages (i.e., tumor-associated macrophages), and clinical outcome. Results: In all cases, the log-rank test revealed that those with high marker scores and macrophage counts (except for marginal CD10+ CAFs) showed significantly worse disease-free survival (DFS). Grade 2/3 cases with high CAF scores (excluding the marginal FAP and CD10 scores) showed significantly worse DFS, whereas those with high intratumoral FAP/CD10 and marginal podoplanin scores showed significantly worse metastasis-free survival (MFS), and those with high intratumoral CD10 score showed significantly worse local recurrence-free survival (LFS). Multivariate analysis identified intratumoral CD10/podoplanin scores and marginal FAP/podoplanin scores as independent prognostic factors for DFS, intratumoral FAP/CD10 and marginal FAP/podoplanin/CD163-positive macrophage scores as independent prognostic factors for MFS, and the intratumoral podoplanin score as an independent prognostic factor for LFS. There was a weak-to-moderate correlation between each score and CD163-positive macrophage counts. Conclusion: Patients with high CAF marker expression in the intratumoral and marginal areas have a poorer outcome. Introduction: The tumor microenvironment of sarcomas has not been studied in detail; in particular, little is known about cancer-associated fibroblasts (CAFs). Sarcoma cells are difficult to distinguish from CAFs, either histomorphologically or immunohistochemically. Methods: We scored the expression of individual CAF markers (fibroblast-activating protein [FAP], CD10, and podoplanin) in the intratumoral and marginal areas of 133 sarcomas. We also examined the association between these markers, as well as the number of CD163-positive macrophages (i.e., tumor-associated macrophages), and clinical outcome. Results: In all cases, the log-rank test revealed that those with high marker scores and macrophage counts (except for marginal CD10+ CAFs) showed significantly worse disease-free survival (DFS). Grade 2/3 cases with high CAF scores (excluding the marginal FAP and CD10 scores) showed significantly worse DFS, whereas those with high intratumoral FAP/CD10 and marginal podoplanin scores showed significantly worse metastasis-free survival (MFS), and those with high intratumoral CD10 score showed significantly worse local recurrence-free survival (LFS). Multivariate analysis identified intratumoral CD10/podoplanin scores and marginal FAP/podoplanin scores as independent prognostic factors for DFS, intratumoral FAP/CD10 and marginal FAP/podoplanin/CD163-positive macrophage scores as independent prognostic factors for MFS, and the intratumoral podoplanin score as an independent prognostic factor for LFS. There was a weak-to-moderate correlation between each score and CD163-positive macrophage counts. Conclusion: Patients with high CAF marker expression in the intratumoral and marginal areas have a poorer outcome.

Introduction: Lysyl oxidase-like 2 (LOXL2) expression and function is frequently altered in different cancers but scarcely explored in oral squamous cell carcinoma (OSCC). This prompted us to investigate the clinical relevance of LOXL2 expression pattern in OSCC and also a possible crosstalk with Hippo/YAP1 pathway signaling. Methods: Immunohistochemical analysis of LOXL2 protein expression was performed in 158 OSCC patient samples, together with Yes-associated protein 1 (YAP1) activation status. Correlations with clinicopathological parameters and patient survival were assessed. Results: Tumor cell-intrinsic LOXL2 expression showed two distinct expression patterns: diffuse cytoplasmic staining (64.6%) and heterogeneous perinuclear staining (35.4%). Remarkably, perinuclear LOXL2 staining was significantly associated with lymph node metastasis, advanced clinical stage and perineural invasion. Moreover, patients harboring tumors with perinuclear LOXL2 expression exhibited significantly poorer disease-specific survival (DSS) rates, and perinuclear LOXL2 positivity gradually increased in relation to YAP1 activation. Patients harboring tumors with concomitant perinuclear LOXL2 and fully active YAP1 exhibited the worst DSS. Multivariate Cox analysis further revealed combined perinuclear LOXL2 and fully active YAP1 as a significant independent predictor of poor DSS. Conclusion: Tumor-intrinsic perinuclear LOXL2 emerges as a clinically and biologically relevant feature associated with advanced disease, tumor aggressiveness, and poor prognosis in OSCC. Moreover, this study unprecedentedly uncovers a functional relationship between perinuclear LOXL2 and YAP1 activation with major prognostic implications. Notably, combined perinuclear LOXL2 and fully active YAP1 was revealed as independent predictor of poor prognosis. These findings encourage targeting oncogenic LOXL2 functions for personalized treatment regimens.

Introduction: Determining a surgical strategy for early-stage lung cancer requires an accurate histologic diagnosis. Immunohistochemistry (IHC) enables reliable diagnosis of histological types but requires more time and more tumor tissue slides than hematoxylin and eosin staining. We aimed to assess the clinical validity of a new rapid multiplex IHC technique utilizing alternating current (AC) mixing for intraoperative lung cancer diagnosis. Methods: Forty-three patients who underwent radical resection of lung cancers were enrolled in a retrospective observational study. Frozen sections were prepared from lung tumor samples, and rapid IHC employing AC mixing was implemented alongside a multiplex IHC protocol targeting thyroid transcription factor-1 + cytokeratin 5, desmoglein 3 + Napsin A, and p63 + tripartite motif containing 29. We then evaluated the concordance between intraoperative diagnoses derived from rapid multiplex IHC and final pathology. Results: The concordance rate between the pathological diagnosis made with added rapid multiplex IHC and the final pathology was 93.0% (Cohen’s \U0001d705 coefficient = 0.860 and 95% CI: 0.727–0.993). When considering only adenocarcinoma and squamous cell carcinoma, the diagnoses were in agreement for all cases. Conclusions: We suggest rapid multiplex IHC as a promising tool for determining surgical strategies for lung tumors.